[ Upstream commit 707aeea13a9c85520262e11899d86df3c4b48262 ]

Remove spin_lock_irqsave in stm32_config_rs485, it cause recursive locking.
Already locked in uart_set_rs485_config.

Fixes: 1bcda09d ("serial: stm32: add support for RS485 hardware control mode")
Signed-off-by: NBorut Seljak <borut.seljak@t-2.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>